Recomendados
Mais conteúdo relacionado
Mais procurados
Mais procurados (20)
Semelhante a Digestivesystem
Semelhante a Digestivesystem (20)
Digestivesystem
- 1. The Digestive System 1
- 2. Digestion • Processing of food • Types – Mechanical (physical) • Chew • Tear • Grind • Mash • Mix – Chemical • Catabolic reactions • Enzymatic hydrolysis – Carbohydrate – Protein – Lipid 2
- 3. Digestion • Phases – Ingestion – Movement – Digestion – Absorption – Further digestion 3
- 4. Digestive System Organization • Gastrointestinal (Gl) tract (Alimentary canal) – Tube within a tube – Direct link/path between organs – Structures • Mouth • Oral Cavity • Pharynx • Esophagus • Stomach • Duedenum • Jejenum • kIleum • Cecum • Ascending colon • Transverse colon 4
- 5. Digestive System Organization • Descending colon • Sigmoid colon • Rectum • Anus • Accessory structures – Not in tube path – Organs • Teeth • Tongue • Salivary glands • Liver • Gall bladder • Pancreas 5
- 6. Anatomy of the Mouth and Throat 6
- 7. Human Deciduous and Permanent Teeth 7
- 8. Dorsal Surface of the Tongue 8
- 9. The Major Salivary Glands 9
- 10. Deglutition (swallowing) • Sequence – Voluntary stage • Push food to back of mouth – Pharyngeal stage • Raise – Soft palate – Larynx + hyoid – Tongue to soft palate – Esophageal stage • Contract pharyngeal muscles • Open esophagus • Start peristalsis 10
- 11. Deglutition (swallowing) • Control – Nerves • Glossopharyngeal • Vagus • Accessory – Brain stem • Deglutition center – Medulla oblongata – Pons – Disorders • Dysphagia • Aphagia 11
- 12. Esophagus • Usually collapsed (closed) • 3 constrictions – Aortic arch – Left primary bronchus – Diaphragm • Surrounded by – SNS plexus – Blood vessels • Functions – Secrete mucous – Transport food 12
- 13. Peristalsis and Segmentation 13
- 14. Esophagus • Sphincters – Upper – Lower • Abnormalities – Achalasia – Atresia – Hernia – Barret’s esophagus – Esophageal varices 14
- 15. Stomach • Usually “J” shaped • Left side, anterior to the spleen • Mucous membrane – G cells – make gastrin – Goblet cells – make mucous – Gastric pit – Oxyntic gland – Parietal cells – Make HCl – Chief cells – Zymogenic cells • Pepsin • Gastric lipase 15
- 16. Anatomy of the Stomach 16
- 17. Stomach • 3 muscle layers – Oblique – Circular – Longitudinal • Regions – Cardiac sphincter – Fundus – Antrum (pylorus) – Pyloric sphincter • Vascular • Inner surface thrown into folds – Rugae • Contains enzymes that work best at pH 1-2 17
- 18. Stomach • Functions – Absorbs – Mix food • Alcohol – Reservoir • Water – Start digestion of • Lipophilic acid • Protein • Nucleic acids • B 12 • Fats – Activates some enzymes – Destroy some bacteria – Makes intrinsic factor – B 12 absorption – Destroys some bacteria 18
- 19. Small Intestine • Extends from pyloric sphincter ileocecal valve • Regions – Duodenum – Jejenum – Ileum • Movements – Segmentation – Peristalsis 19
- 20. Small Intestine • Histology – Intestinal glands – Intestinal enzymes – Duodenal glands – Alkaline mucous – Paneth cells – Lysozyme – Microvilli – Lacteals – Plica circularis – Smooth muscle – Lymphatic tissue – GALT – Vascular 20
- 21. Small Intestine • Absorbs – Lipids – 80% ingested water • Monoglycerides – Electrolytes • Fatty acids – Vitamins • Micelles – Minerals • Chylomicrons – Carbonates • Active/facilitated transport • Monosaccharides – Proteins • Di-/tripeptides • Amino acids 21
- 22. Structure of the Villi in the Small Intestine 22
- 23. Small Intestine • Secretes digestive enzymes – Peptidases • Amino- • Di- • Tri- – Sucrases – Maltase – Lactase – Saccharidases • Di- • Tri- – Lipase – Nucleases 23
- 24. Small Intestine • Control • Requires pancreatic enzymes & bile to complete digestion 24
- 25. Large Intestine • Extends from ileocecal valve to anus • Regions – Cecum – Appendix – Colon • Ascending • Transverse • Descending – Rectum – Anal canal 25
- 26. Anatomy of the Large Intestine 26
- 27. Large Intestine • Histology – No villi – No permanent circular folds – Smooth muscle • Taeniae coli • Haustra – Epiploic appendages – Otherwise like rest of Gl tract 27
- 28. Large Intestine • Functions – Mechanical digestion – Absorbs • Haustral churning •More water • Peristalsis •Vitamins –B • Reflexes –K – Gastroileal – Gastrocolic – Concentrate/eliminate wastes – Chemical digestion – Bacterial digestion • Ferment carbohydrates • Protein/amino acid breakdown 28
- 29. Feces Formation and Defecation • Chyme dehydrated to • Control form feces – Parasympathetic • Feces composition – Water – Voluntary – Inorganic salts – Epithelial cells – Bacteria – Byproducts of digestion • Defecation – Peristalsis pushes feces into rectum – Rectal walls stretch 29
- 30. Liver • Location – R. Hypochondrium – Epigastric region • 4 Lobes – Left – Quadrate – Caudate – Right • Each lobe has lobules – Contains hepatocytes – Surround sinusoids – Feed into central vein 30
- 31. Liver • Functions – Makes bile • Detergent – emulsifies fats • Release promoted by: – Vagus n. – CCK – Secretin • Contains – Water – Bile salts – Bile pigments – Electrolytes – Cholesterol – Lecithin 31
- 32. Liver – Detoxifies/removes • Drugs • Alcohol – Stores • Gycolgen • Vitamins (A, D, E, K) • Fe and other minerals • Cholesterol – Activates vitamin D – Fetal RBC production – Phagocytosis – Metabolizes absorbed food molecules • Carbohydrates • Proteins • Lipids 32
- 33. Liver • Dual blood supply – Hepatic portal vein • Direct input from small intestine – Hepatic artery/vein • Direct links to heart 33
- 34. The Duodenum and Related Organs 34
- 35. The Organs and Positions in the Abdominal Cavity 35
- 36. Structures of the Alimentary Canal 36